Predictive software license balancing

ABSTRACT

A predictive software license balancing system for allocating a predetermined number of software licenses between two or more license servers located at different sites. Each license server compiles software license usage statistics and shares the usage statistics with the other license servers. Based in the compiled software license usage over time, the software license usage for each site is predicted and the available software licenses distributed accordingly, thus balancing the number of software licenses available at each site based on predicted software license usage.

FIELD OF THE INVENTION

[0001] The invention relates to software licensing, and in particular to a system for controlling the number of users that concurrently use a licensed software file.

PROBLEM

[0002] It is a problem in the software field to prevent unauthorized users from accessing and using an application file while also providing a method to allow customers to purchase and concurrently use more than one copy. A number of software publishers license software files under a pricing model wherein a customer purchases the right to concurrently use a predetermined number of copies. Software files that are sold for concurrent use are often delivered with license management software installed on a license server, from which the customer requests software licenses. The licensing management software ensures that the customer does not use more licenses than they have purchased and are entitled to use. A problem arises when a customer attempts to share use of the application files at more than one site.

[0003] Effective management of multiple copies of application files and “floating licenses” presents a major dilemma for computer site administrators and software application publishers. The focus of control for managing multiple copies of an application file or application file software license is the physical location of the application file or the program disk. The details of controlling physical access and the degree of inconvenience vary, but in a world of hard disks, networks, file servers and electronic email, management based on controlled distribution is intrinsically impractical or even impossible. Without any practical tools, site administrators are forced to rely on a rather ill defined “reasonable effort” at software license compliance. Three solutions have commonly been used.

[0004] The first solution has been to run the license management software at only one site and require users at other sites to request a software license across a wide-area-network (WAN) as described in U.S. Pat. No. 5,742,757. There are disadvantages to this approach. Software license requests across a WAN can be slow, and if the WAN connection goes down, some sites may be unable to request software licenses. A solution to the problem is to break the software licenses into subsets and provide each site with its own license server, licensing management software and a set of software licenses. Using this solution, users at each site contact their local license server first. If the license server does not have a license available, the user is required to request a license from another server across the WAN. However, the user has no way of knowing which license server has a software license available. The problem is exasperated when additional sites are added, providing fewer software licenses at each site and additional sites to contact to request a software license.

[0005] A third solution, a licensing product named “KeyServer” from Sassafras Software of Hanover N.H., solves the previously discussed problems by providing a system that allows “ghost servers”. Customers purchase and use KeyServer to control the number of concurrent application users so that the business does not use more software licenses than the business has purchased and therefore has a right to use. Ghost servers are placed at each site and handle software license requests from clients at those sites. Ghost servers obtain software licenses from a central license server. If a ghost server can not contact the central license server, the ghost server acts as the central license server. While this solution offers a very reliable system, a problem arises with controlling licensing limits. When the central license server is not available to the ghost servers, each ghost server acts as the central license server, enabling each ghost server to allow access to the entire software license count at each and every site. Whether intentional or inadvertent, failure of the central license server provides a method for exceeding license limits.

[0006] For these reasons, a need exists for a system to track the number of software licenses used at each license server site, analyze software license usage at each site, and allocate a set of software licenses to each site based on the sites predictive software license usage.

Solution

[0007] The predictive software license balancing system authorizes concurrent use of an application file at multiple sites. Initially, the plurality of software licenses are divided among the multiple sites. A license server located at each site accepts software application file usage requests from users at that particular site. If a software license is available when the request is received, the user is granted an authorization to access and use the corresponding application file. The multiple license servers are interconnected via a WAN or other network connection. As concurrent usage of an application are authorized at the multiple sites, the license servers record the application file usage statistics relating to the number of software licenses available and number of concurrent users authorized during a predetermined time period and exchange the usage statistics with the other license servers. Using the usage statistics from the multiple license servers, the percentage of application file concurrent usage at the multiple sites is calculated. Using the usage statistics gathered over a period of time, the application file concurrent usage for each site is predicted and software licenses distributed accordingly.

[0008] In the event communication between one license server and the other license servers temporarily fails, the disconnected license server would continue to operate based on the previous predictions. The other license servers would continue to rebalance software license distribution between the communicating license servers using previous predictions for the disconnected license server. When the connection is re-established, new usage statistics are shared and new predictions calculated and the software licenses are redistributed according to the predictions. Following a complete failure of a license server, connection with the other license servers is established and valid usage statistics retrieved from one of the other license servers.

[0009] If connection to the other license servers were not reestablished within a time period, the disconnected license server may consider the failure to be permanent. Following a permanent failure, the license server would revert to a default set of software licenses available for authorizing concurrent application file usage at that particular site. In this embodiment, the other connected license servers may rebalance the software licenses based on the default set of software licenses available for the disconnected license server.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 illustrates a block diagram of a multi-site organization using the present predictive software license balancing system;

[0011]FIG. 2 is a flow diagram of software license balancing using the present predictive software license balancing system;

[0012]FIG. 3 is an operational flow diagram of the present predictive software license balancing system;

[0013]FIG. 4 is an operations flow diagram of the present predictive software license balancing system; and

[0014]FIG. 5 is another operations flow diagram of the present predictive software license balancing system.

DETAILED DESCRIPTION

[0015] The predictive software license balancing system summarized above and defined by the enumerated claims may be better understood by referring to the following detailed description, which should be read in conjunction with the accompanying drawings. This detailed description of the preferred embodiment is not intended to limit the enumerated claims, but to serve as a particular example thereof. In addition, the phraseology and terminology employed herein is for the purpose of description, and not of limitation.

[0016] A number of software providers license software files under a pricing model wherein a customer purchases the right to concurrently use a predetermined number of copies of an application file, referred to as “floating licenses”. Software files that are sold with “floating licenses” are often delivered with license management software installed on a license server, from which users request software licenses. The licensing management software ensures that the customer does not use more licenses than they have purchased and are entitled to use.

[0017] Predictive Software License System Configuration—FIG. 1:

[0018] The present predictive software license balancing system is configured to operate between two or more sites. Referring to the block diagram in FIG. 1, a set of software licenses is shared amongst three sites 110, 120 and 130. Each site includes a license server, 112, 122, and 132, for controlling application file authorization at the particular site. License servers 112, 122, and 132 are linked together via a communication channel 140 such as a wide area network (WAN) for sharing application file usage statistics.

[0019] In the example illustrated in FIG. 1, eight licensed copies of the application file are available for concurrent usage by users at three sites 110, 120 and 130. Initially the software licenses are divided into subsets and distributed among the three sites 110, 120 and 130. Each license server 112, 122 and 132 receives application file usage requests from users at the particular site, if a software license is available, the user is granted an authorization to access and use the corresponding application file.

[0020] Software License Balancing—FIGS. 1 and 2:

[0021] Referring to the flow diagram in FIG. 2, the license server, such as license server 112, records application file usage statistics in step 220 for site 110 for a period of time. The application file usage statistics complied in step 220 by each license server 112, 122 and 132 are distributed to the other license servers in step 230 where they are stored in memory for use in calculating the percentage of concurrent application file usage of each license server. Using the shared application file usage statistics from step 230, the percentage of concurrent application file users for each site is calculated in step 240 by processing devices within each license server. Each server is performing the same calculations using the same statistics, therefore each license server will calculate the same percentage of concurrent application file users. Each license server records the results for future use and makes available a corresponding number of application files in step 260 which will be authorized as application file usage requests are received. Compilation of application file usage statistics by the processing device at each site over a predetermined period of time provides the statistics required for predicting future application file usage in step 250. Once application file usage predictions are calculated in step 250, the number of application files available for use at each site are recalculated in step 260 according to the predictions, thus balancing the software license distribution.

[0022] For example, if sites 110 and 130 authorize three concurrent users to access and use the application file between the hours of 8 am and 5 pm, sites 110 and 130 each use approximately forty-percent of the available software licenses. Site 120 application file usage during the same time period is one in this example. Therefore the eight software licenses are initially distributed in step 210 with a subset of three software licenses distributed to each site 110 and 130 and the remaining two software licenses are distributed to site 120. In step 270, the license server at each site manages authorization of concurrent usage for that particular site.

[0023] Providing a method for compiling and sharing application file usage statistics between the multiple license servers reduces the time required to request a software license from a central license server and balances the number of software licenses available at each particular site. By balancing the number of software licenses available at each license server based on predicted application file usage reduces the need to transfer software licenses between license servers, thus saving time. A multi-site organization using the present predictive software licensing balancing system reduces the WAN traffic required by prior art license distribution systems to request and transfer software licenses. Instead, WAN bandwidth is required only for sharing application file usage statistics and the application file usage statistics can be schedule for distribution during optimal times.

[0024] Operational Characteristics—FIGS. 1, 2 and 3:

[0025] Referring to the block diagram in FIG. 1 in conjunction with the operational flow diagram in FIG. 3, site 110 received software application file usage requests in step 310 from three users, 114, 115 and 116. As license server 112 receives a license request from a user, the processor within the license server 112 checks the number of software licenses available for site 110 that were recorded in memory. Since three software licenses are available, user 114 is first granted authorization to use the application file. The processor records the number of software licenses granted along with the number of software licenses available. When users 115 and 116 request a software license, the processor checks both the number of software licenses available and the number of software users authorized. If software licenses are available, the license server authorizes the users in step 324 to access and concurrently use the application files in step 326. Likewise, license server 122 authorizes usage in step 324 to user 124 while license server 132 authorized concurrent usage of the application file in step 324 to the first three users requesting software licenses in step 310, users 134, 135 and 136 in this example. License server 122 has one software license available while license servers 112 and 132 have granted all available software licenses.

[0026] When license server 132 receives an application file usage request in step 310 from user 137, license server 132 determines in step 320 whether a software license is available. If a software license is not available in step 320, license server 132 sends a software license request to an alternative license server, such as license server 122, in step 330. License server 122 has authorized one user and has one software license available. The request for a software license is granted by license server 122 to requesting license server 132 in step 342. Each license server updates the number of software licenses available at the two sites. License server 122 now has one software license available and one software license granted. If a subsequent user requests usage of the application file, server 122 would have to deny the request unless another license server such as license server 112 or 132 have a software license available. Likewise, license server 132 updates records to show four software licenses available. In step 137, license server 132 authorizes concurrent use to user 137 allowing user 137 to access and use the application file in step 346.

[0027] In the event that there is not a software license available at the three sites 110, 120 and 130, the application file usage requester, user 137 in this example, is queued for authorization to concurrently use the application file when a software license is available from any one of the three sites 110, 120 or 130. In this example, license server requested a software license from license servers 112 and 122. The requests were denied since license servers 112 and 122 have granted concurrent use of the software licenses available for their particular site. The request remains active at each license server 112, 122 and 132 until a user terminates use of an application file, at which time the request from license server 132 is granted.

[0028] Referring to FIG. 2, the application file usage for each site is compiled by the site license server in step 220 and shared with the other license servers in step 230. Using previously collected software application file usage statistics from each site in conjunction with the new application file usage statistics, future application file usage is predicted in step 250. The software licenses are redistributed accordingly in step 260, thus balancing the number of software licenses available at each site. The multiple site license servers continue to share application file usage statistics, predict future application file usage requirements for each site and to redistribute the software licenses accordingly.

[0029] Predictions may also be based on usage statistics by time-of-day or day of the week. For example, license servers on opposite coasts or in different countries may share software licenses and use the software licenses at different times, thus providing more software licenses available at each site without the purchase of additional software licenses. Software applications are licenses for 24-hour use although many businesses only use the application files during an eight or ten hour day. Sharing the software licenses with a site using the application file during opposite hours saves the cost associated with purchasing twice as many software licenses.

[0030] Failure Mode—FIGS. 1 and 4-5:

[0031] Failure of the communication channel in step 400 between one license server and the other license servers does not prevent each license server from managing the authorization of concurrent application file usage at that particular site in step 410. Instead, the disconnected license server continues to manage application file usage requests in step 410 based on the stored predictive license balancing. Likewise, the other two license servers manage concurrent usage in step 410 at their particular site based on previously calculated application file usage predictions. However, the connected license servers continue to collect and share application file usage statistics in steps 420 and 430. Using the new application file usage statistics combined with the previously recorded application file usage statistics for the disconnected license server, the connected license servers predict future application file usage statistics in step 440 and redistribute software licenses accordingly, taking into account the number of concurrent users predicted for the disconnected license server. Meanwhile, the disconnected license server continues to collect application file usage statistics. In step 450 when the connection is restored, the application file usage statistics are shared in step 460 with the other license servers and new application file usage predictions calculated and each license server continues to manage software licenses at their particular site in step 470

[0032] Referring to the operational flow diagram of FIG. 5, application file usage statistics and predictions are temporarily saved in memory in step 500. They are not permanently saved on the license server to eliminate the susceptibility of tampering with the statistics or predictions. Therefore, complete failure of a license server in step 510 results in stored application file usage statistics and predictions being lost. When the failed license server reinitializes, connection with the other license servers is established in step 520. If usage statistics are available in step 550, the previously failed license server retrieves the usage statistics and previously calculated predictions in step 540 and operation between the multi-site license servers proceeds as usual in step 580. However, if the previously failed license server is unable to reestablish connection with the other license servers in step 520, all is not lost. Instead, the previously failed license server reverts back to the default software license subset in step 540. Thus, regardless of the status of reconnection with the other license servers, the previously failed license server manages the default subset of software licenses in step 542 until connection is reestablished. Unlike prior art software license management systems, providing a method for license servers that are not able to communicate with other license servers to continue to manage a default subset of software licenses prevents more than one site from granting the concurrent usage of the total number of software licenses. It also provides a method for each site to continue managing application file usage requests at each corresponding site.

[0033] If application file usage statistics are not available in step 550 from another license server after the communication channel is restored in step 520, the previously failed license server manages the default software license subset in step 560 and collects and shares updated application file usage statistics in step 562.

[0034] A catastrophic failure of all of the license servers simultaneously would result in each license server initializing with the default subset of software licenses. Each license server would collect and share new application file usage statistics as previously discussed. In an alternative embodiment, the usage statistics are periodically sent to an alternative remote storage device. In this embodiment, if all of the license servers fail simultaneously, the first license server reinitialized recovers the previously saved usage statistics from the remote storage device. As the other license servers reinitialize, the other license servers recover usage statistics from the first license server and operation presumes.

[0035] As to alternative embodiments, those skilled in the art will appreciate that the present predictive software license balancing system can be configured with an alternative number of sites, license servers and available software licenses. It is also anticipated that the multi-site license servers receive and process software application file usage requests for more than one application file type and that the usage statistics and predictions for each application file type are calculated and distributed independent of the other application file types. Likewise, a single file may contain an application that supports a number of different features that may be individually turned on or off with licenses. Therefore the term application file has been illustrated and described as an example of usage of the present predictive software license balancing system and not as a limitation of usage.

[0036] While the present predictive software license balancing system has been illustrated and discussed for use in a multi site situation, usage is not intended to be limited to businesses having multiple sites. The present predictive software license balancing system may be utilized with license servers connected within a Local Area Network (LAN) or a software licensing system having multiple software servers at one or more sites wherein each of the multiple license servers is treated as being a separate site.

[0037] It is apparent that there has been described, a predictive software license balancing system that fully satisfies the objects, aims, and advantages set forth above. While the predictive software license balancing system has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and/or variations can be devised by those skilled in the art in light of the foregoing description. Accordingly, this description is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the appended claims. 

What is claimed is:
 1. A software license distribution system for authorizing usage of a plurality of application files to a plurality of users, the system comprising: a plurality of software licenses corresponding to the plurality of application files, wherein each one of the plurality of software licenses authorizes usage of the corresponding one of the plurality of application files; one or more usage requests from the plurality of users; a first user authorization controller located at a first site for receiving said one or more usage requests from a first set of the plurality of users located at the first site; a second user authorization controller located at a second site for receiving said one or more usage requests from a second set of the plurality of users located at the second site; wherein the first and second user authorization controllers comprise: a means for generating a software license usage statistic; a communication channel interconnecting the first and second user authorization controllers for exchanging the software license usage statistic; and a means for calculating a predicted software license usage from the software license usage statistics from the first and second user authorization controllers, wherein the first and second user authorization controllers authorize usage of the plurality of application files according to the predicted software license usage.
 2. The software license distribution system of claim 1 further comprising: a storage device having a memory for storing the software license usage statistics and the predicted software license usage; and an interconnecting means for interconnecting the first and second user authorization controllers to the storage device for receiving/sending the software license usage statistics and the predicted software license usage from/to the first and second user authorization controllers.
 3. The software license distribution system of claim 2 wherein when the first and the second user authorization controllers reinitialize at least one of the first and second user authorization controllers retrieves the software license usage statistics and the predicted software license usage from the storage device and sends the same to the other one of the first and second user authorization controllers.
 4. The software license distribution system of claim 1 wherein the first and second user authorization controller further comprise: a memory means for saving the software usage statistic and the predicted software license usage; and wherein when the communication channel between the first and second user authorization controller fails the first and second user application controllers continue to receive the one or more usage requests and authorizes usage based on the saved predicted software license usage.
 5. The software license distribution system of claim 4 wherein when the communication channel is reestablished, the first and the second user authorization controllers send/received the corresponding software file usage statistic to/from the other first and second user authorization controller.
 6. The software license distribution system of claim 1 wherein the first and second user authorization controllers further comprise: a first and second subset of the plurality of software licenses respectively, wherein when the first and second user authorization controllers initialize the first and second user authorization controllers manage the corresponding first and second subset of the plurality of software licenses.
 7. The system of claim 6, wherein said first and second user authorization controllers further comprise: a memory means for saving the corresponding first and second subset of plurality of software licenses for use when said first and second user authorization controllers are initialized.
 8. The software license distribution system of claim 6 wherein the first and second user authorization controllers periodically update the predicted software license usage and grant the one or more application file usage requests based on the updated predicted software license usage.
 9. A predictive software license balancing system for managing a plurality of software licenses, the system comprising: a plurality of application files corresponding to the plurality of software licenses; a plurality of usage requests from a plurality of users; two or more license controllers, each one of the two or more license servers located at one of two or more sites, the two or more license controllers comprising: a means for distributing a corresponding subset of the plurality of software licenses to the two or more license controllers, wherein each one of the two or more license controllers manages the corresponding distributed subset of the plurality of software licenses; a means for receiving a subset of the plurality of usage requests from a subset of the plurality of users located at the corresponding one of the two or more sites; a processing means for processing the corresponding subset of the plurality of usage requests; a means for calculating an application file usage statistic; two or more communication channels between the two or more license controllers for sending/receiving the application file usage statistics to/from the two or more license controllers; a means for predicting a future application file usage from the application file usage statistics from said two or more license controllers, a means for redistributing the plurality of software licenses based on the future application file usage from the two or more license controllers.
 10. The predictive software license balancing system of claim 9 wherein the two or more license controllers further comprise: a memory means for saving the software usage statistic and the future software license usage; and wherein when one of the two or more communication channels between the two or more license controllers fails the disconnected one of the two or more license controllers continues to receive the corresponding subset of the usage requests and authorize usage based on the saved predicted application file usage.
 11. The predictive software license balancing system of claim 10 wherein when the one of the two or more communication channels is reestablished, the two or more license controllers send/received the corresponding application file usage statistic to/from the other two or more license controllers.
 12. The predictive software license balancing system of claim 9 further comprising: a means for balancing the number of software licenses within each corresponding subset of the plurality of software licenses based on the future application file usage; a means for periodically updating the future application file usage; and a means for redistributing the plurality of software licenses to the two or more license controllers based on the updated future application file usage and responding to the subset of usage requests based on the updated future application file usage for the corresponding one of the two or more license controllers.
 13. A method for a software distribution system to distribute a plurality of software licenses corresponding to a plurality of application files to two or more license controllers interconnected via a communication channel, wherein each one of the two or more license controller is located at a corresponding one of two or more sites, each of the two or more license controller having a means for processing a plurality of usage requests from a plurality of users located at a corresponding one of the two or more sites, the method comprising: distributing a default subset of the plurality of application files to each one of the two or more license controllers; each one of the two or more license controllers, authorizing usage of the default subset of the plurality of application files, the authorization comprising: processing one of a subset of the plurality of usage requests; recording the number of usage requests authorized; authorizing a usage of a corresponding application file when the number of usage requests authorized is less than the number of application files within the corresponding subset of the plurality of application files; balancing the number of application files in the corresponding subset of the plurality of application files, the balancing comprising: calculating a first application file usage statistic; sending/receiving the first application file usage statistic to/from the two or more license controllers; predicting a first future application file usage based on the first application file usage statistics from the two or more license controllers; and redistributing the plurality of application files between the two or more license controllers according to the first predicted application file usage for each one of the two or more license controllers.
 14. The distribution method of claim 13 wherein authorizing usage further comprises: if one of the subset of the plurality of application files is not available, requesting one of the subset of the plurality of application files from another one of the two or more license controllers; if one of the subset of the plurality of application files is available from another one of the two or more license controllers, authorizing usage of the one of the subset of the plurality of application files, the authorization comprising: transferring usage of the one of the subset of the plurality of application files to the requesting one of the two or more license controllers; authorizing usage of the transferred one of the subset of the plurality of application files in response to the one of the plurality of usage requests; and adjusting the number of application files within the corresponding subsets of the plurality of application files to reflect transfer/receipt of the one of the subset of the plurality of application files.
 15. The distribution method of claim 14 further comprising: if one of the plurality of application files is not available at the two or more license controllers, queuing the one or more application file usage requests; and when one or more of the plurality of application files becomes available at one of the two or more license controllers, authorizing the usage of the one of the plurality of application files in response to the one or more queued application file usage requests.
 16. The distribution method of claim 13 wherein if the communication channel between the two or more license controllers fails, the method further comprising: the disconnected one of the two or more license controllers, authorizing usage of the subset of the plurality of application files based on the default application file usage; and the remaining connected two or more license controllers, authorizing usage of the subset of the plurality of application files based on the future application file usage, the authorization comprising: calculating a second application file usage statistic based on the number of application file requests authorized by the connected two or more license controllers; and predicting a second future application file usage based on the second application file usage statistics from the connected two or more license controllers and the default subset of the application files corresponding to the disconnected one of the two or more license controllers; redistributing the plurality of application files based on the second future application file usage and the default subset of the application files corresponding to the disconnected one of the two or more license controllers.
 17. The distribution method of claim 13 wherein the software distribution system further comprises a storage device interconnected to the two or more license controllers, the method further comprising: storing the application file usage statistics from the two or more license controllers and the predicted software license usage for the two or more license servers on the storage device; when the two or more license controllers reinitialize, retrieving the application file usage statistics and the predicted software license usage from the storage device; and distributing the plurality of application files based on the retrieved the predicted software license usage. 